/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * FDS Conversion
 *
 */

#include "mapinc.h"


static void FP_FASTAPASS(1) Mapper50IRQ(int a) {
	if (IRQa) {
		if (IRQCount < 4096)
			IRQCount += a;
		else{
			IRQa = 0;
			X6502_IRQBegin(FCEU_IQEXT);
		}
	}
}

static void M50Restore(int version) {
	setprg8(0xc000, mapbyte1[0]);
}

static DECLFW(M50W) {
	if ((A & 0xD060) == 0x4020) {
		if (A & 0x100) {
			IRQa = V & 1;
			if (!IRQa) IRQCount = 0;
			X6502_IRQEnd(FCEU_IQEXT);
		}else {
			V = ((V & 1) << 2) | ((V & 2) >> 1) | ((V & 4) >> 1) | (V & 8);
			mapbyte1[0] = V;
			setprg8(0xc000, V);
		}
	}
}

void Mapper50_init(void) {
	SetWriteHandler(0x4020, 0x5fff, M50W);
	SetReadHandler(0x6000, 0xffff, CartBR);
	MapStateRestore = M50Restore;
	MapIRQHook = Mapper50IRQ;

	setprg8(0x6000, 0xF);
	setprg8(0x8000, 0x8);
	setprg8(0xa000, 0x9);
	setprg8(0xc000, 0x0);
	setprg8(0xe000, 0xB);
}

